Conventional methods for battery charging are cumbersome, time-consuming, and error-prone. Current battery chargers capable of charging batteries of different voltages require users to manually select a voltage rating of the battery to be charged in order for the battery to be properly charged, and not damaged by the charging process. If a user selects a wrong battery voltage rating, the battery may not be properly charged, and the battery and/or the charger may be permanently damaged.
Manual selection of the battery voltage, however, is subject to the user actually knowing the proper battery voltage rating, and correctly selecting the voltage rating on the battery charger itself. Because rechargeable batteries can have different voltage ratings, even among batteries with the same form factor, the voltage rating of a specific battery may not be obvious to a user. Furthermore, physically selecting a voltage rating on a battery charger may be hampered by environmental conditions, such as darkness or moisture, or deterioration of the controls on the battery charger itself.
Thus there is a need for chargers that automatically detect the voltage of a battery.